Heat Shock Proteins and Cardiovascular Pathophysiology

Abstract

In the eukaryotic cell an intrinsic mechanism is present providing the ability to defend itself against external stressors from various sources. This defense mechanism probably evolved from the presence of a group of chaperones, playing a crucial role in governing proper protein assembly, folding, and transport. Upregulation of the synthesis of a number of these proteins upon environmental stress establishes a unique defense system to maintain cellular protein homeostasis and to ensure survival of the cell. In the cardiovascular system this enhanced protein synthesis leads to a transient but powerful increase in tolerance to such endangering situations as ischemia, hypoxia, oxidative injury, and endotoxemia. These so-called heat shock proteins interfere with several physiological processes within several cell organelles and, for proper functioning, are translocated to different compartments following stress-induced synthesis. In this review we describe the physiological role of heat shock proteins and discuss their protective potential against various stress agents in the cardiovascular system.

The influence of extremely low frequency magnetic fields on cytoprotection and repair

“…Hsp72). The members of the HSP70 class bind to proteins in an energy-dependent (ATP) manner and help to maintain or restore the proper conformation of other proteins in the cell through a repetitive process of binding, bending, and release [Snoeckx et al, 2001]. They also play a role in keeping proteins unfolded until they reach their final destination in the cell or in trafficking irreversibly damaged proteins to lysosomes [Kiang and Tsokos, 1998].…”

“…These bound complexes are very stable, which means that Hsp27 is able to bind to inactivated proteins and hold them in a recoverable state until normal physiological conditions are restored, and refolding can be performed by other chaperones such as Hsp70. Actin, in particular, has been found to be protected by the small HSPs [Snoeckx et al, 2001], which is important not only for the cytoskeleton of all cells, but also for the sarcomeres in cardiac tissue. In addition to preconditioning studies, which tend to induce a variety of protective stress proteins, transgenic studies in vitro [Martin et al, 1997;Brar et al, 1999;Vander Heide, 2001] have demonstrated that increasing levels of Hsp25/27 prior to simulated ischemia-reperfusion injuries can have a protective effect.…”

“…Often, the so-called inducible form of Hsp70 is found at detectable levels in certain tissues, such as the heart, while the constitutive form also exhibits some degree of inducibility. However, cerebral tissue tends to have a vastly subdued heat shock response [Snoeckx et al, 2001], which may impact the ability of magnetic fields to protect brain tissue from ischemic stroke. Furthermore, the sensitivity of the HSP response to EM fields may have a genetic component [DiCarlo and Litovitz, 1999;Lin et al, 2001], which may explain the different results obtained by different studies.…”

Heat Shock Protein 27(HSP27) in Kidney Disease: Potentials for Diagnosis and Therapy

“…Elevated post-ischemic expression of HSP27 may account for the reduced disruption of tubular epithelium cytoskeleton, attenuation of OS 24,37,38 , plus stabilizing of microfilaments, preventing protein dysfunction 39 and reducing ischemia induced membrane lipids degradation. [40][41][42] The lack of HSPs alongside degenerative lesions in the renal tubular epithelial cells may lead to electromechanical dissociation, resulting in acute renal failure. 43 …”

Differential expression of myocardial heat shock proteins in rats acutely exposed to fluoride

“…The induction of Hsps is based on the nature of the toxic stimulus (Kalmar and Greensmith 2009). The selection of these Hsps in the present study was mainly based on their role in various xenobioticinduced cardiotoxic and cardiovascular disease models (Lin et al 2007;Snoeckx et al 2001). The expression profile of these Hsps is mainly used to monitor the cardiac pathophysiological consequences upon xenobiotic insults.…”